The variable displacement pump has been playing up recently! When the pressure is reduced to idle, which should be about 14bar, sometimes the pump pulses at around 35 to 45 bar. I took a video of this happening so that I can show the bosch rep. I have checked various signals to the pressure relief valve etc but can't see anything wrong. I also cleared the 0.8mm orifice but again i don't think it was blocked.